Again a little smoother, at least most of the jello is gone. I can finetune it a little more, but this is already pretty acceptable. After weeks of messing with the PIDs and filters, I remembered adjusting the TPA is also important to remove oscillations.
Finally getting close to smooth recordings.
Read here about TPA: https://github.com/cleanflight/cleanflight/blob/master/docs/PID%20tuning.md